JPH0375589B2 - - Google Patents

Description

[Detailed description of the invention]

This invention causes dusting (expansion and collapse) during the cooling process and scatters as dust during handling, worsening the working environment, and currently most of the material is disposed of in landfills. This relates to the effective use of steelmaking slag. There are various types of steelmaking slag, and the present invention uses high basicity slag for ordinary steel in the reduction stage, special steel for electric furnaces, converters, and continuous casting (hereinafter referred to as
CC) target slag. Currently, these slags are placed in a slag pot and are heated to about 3~
After cooling for 12 hours, it is discharged at about 200-300℃
When 2CaO・SiO ₂ transitions from β to γ,
It causes dusting and scatters, making the work environment worse. In addition, after being sprinkled with water to prevent it from scattering during transportation, it is disposed of in a landfill. The present invention solves the above-mentioned drawbacks and relates to a method for effective utilization of water so that α′~β−2CaO・SiO ₂ is mainly composed of α′−β−2CaO・SiO 2 or mainly glass or a part of α′−β−2CaO・SiO ₂ and glass is mainly used. After drying the slag, it is crushed and treated with an alkaline stimulant (e.g. CaO, Ca(OH) ₂ , Na ₂ CO ₃ ,
It was discovered that by adding a small amount of NaOH (such as NaOH) and kneading with water, it has hydraulic properties. The gist of this is a method of using high basicity steelmaking slag, which involves converting high basicity steelmaking slag in a molten state into slag, drying it, adding gypsum or lime to it, crushing it, and using it as a sludge solidification agent or soil conditioner. be. Below, we will show experiments and results conducted to confirm the effects of the present invention. Table 1 shows the chemical analysis values and properties of the samples used in the experiment.

[Table] Next, Table 2 shows the melting temperature (in a Seegel cone according to the JIS method) of each sample. After drying the sample in a constant temperature dryer (maintained at 105-110℃) for more than 24 hours, it was placed in an electro-fused magnesia crucible.
Put 500g in siliconite electric furnace (maintained at 1580℃)
Re-dissolve the water, take it out of the furnace and cool it in water to make granulated water. After drying, crush it to about 200 mesh or less, add and mix 3% by weight of lime, add water and knead, and then put it in a plastic bag. The hardening condition was examined and shown in Table 3.

【table】

[Table] In addition, ◎ means that it is very hard even when pressed by hand, and ○
indicates that it is the same hardness, △ indicates that it is slightly hard, and × indicates that it is not cured. The chemical analysis values, minerals formed, etc. of several examples were investigated and are shown in Table 4.

[Table] Also, sludge with an attached moisture content of 30.5% (kaolinite,
In the same way as described above, each prototype sample was crushed (to about 200 mesh or less), 3% by weight of lime and gypsum were added as stimulants, and mixed in a mortar bowl. , Packed in three layers using a soil testing mold rammer (JIS method)
Table 5 shows the results of examining the compressive strength after one month of moist air curing.

【table】

[Table] As described above, according to the method of the present invention, by cooling the molten state in water and pulverizing it, the mineral composition can be changed to mainly α′ and β-2CaO・SiO ₂ and glass. Instead of using hydraulic slag, a small amount of lime or gypsum is added and the pulverized product has the effect of hardening sludge, etc., in the same way as when cement or blast furnace slag powder is used.

Claims (1)

[Claims] 1. A method of using high basicity steel slag in which the molten high basicity steel slag is turned into slag, dried, crushed with the addition of gypsum or lime, and used as a sludge solidification material or soil conditioner.